Work on this project will concern two differentiation processes in bacteria: sporulation in Bacillus species and encystment in Azotobacter vinelandii. Phage isolated from temperature sensitive sporulation mutants will be tested for their ability to transduce markers into auxotrophs of B. cereus. The phage appears to be carried in the parent in a pseudolysogenic state. The nature of the phage DNA and the mode of its replication and expression will be investigated. 50s ribosome of B. lichiniformis cells will be treated with sporulation-specific protease and then the proteins fractionated by methods currently applied to ribosomes to determine which are the source of the antibiotic Bacitracin. Differential labelling H3 or C14 -amino acids) will also be utilized in these studies. Tracer studies, the use of fluorescent probes, and membrane- specific enzyme reactions all indicate that B-hydroxybutyrate, the specific inducer of encystment in A. vinelandii, is rapidly incorporated into phospholipids thereby producing striking changes in membrane properties. We will isolate encystment P-lipid, characterize it, and attempt to ehange it with isolated membrane from vegetative cells to produce encystment-specific changes in their properties. The specificity of RNA polymerase of A. vinelandii will be studied as a function of the stage in life cycle of the organism. Isolation of the enzyme will be by antibody precipitation and "factors" will be looked for by gel electrophoresis. A continuing effect will be made to isolate auxotrophic mutants or a mating system in A. vinelandii.